JP2022050351A - Mounting structure and mounting method for steering gear box - Google Patents

Abstract

To provide a mounting structure for a steering gear box, in which a difference in responsiveness between left and right steering operations is small, and to provide a mounting method therefor.SOLUTION: A mounting structure for a steering gear box is a mounting structure of a gear box 52, accommodating a rack shaft that is displaced in a vehicle width direction by a steering force, on a front sub-frame 3, the gear box 52 is fixed to the front sub-frame 3 of a vehicle body, in a left mount portion 57L and a right mount portion 57R provided at positions apart along an axial direction of the rack shaft and in a central mount portion 57C provided between the left mount portion 57L and the right mount portion 57R in the axial direction. The central mount portion 57C is fixed to the front sub-frame 3 via a mount bush having a rubber member. The left mount portion 57L and the right mount portion 57R are fixed to the front sub-frame 3 more rigidly than the central mount portion 57C.SELECTED DRAWING: Figure 1

Description

The present invention relates to a steering gearbox mounting structure and mounting method. More specifically, the present invention relates to a mounting structure and a mounting method of the gearbox of the steering device to the vehicle body.

The steering device includes a pinion shaft that rotates according to the steering operation of the steering wheel by the driver, a rack shaft that meshes with the pinion of the pinion shaft and displaces along the axis when the pinion shaft rotates, and these rack shafts and pinions. It is equipped with a gearbox for accommodating. The gearbox of the steering device is fixed to the vehicle body in a state where the axis of the rack axis and the vehicle width direction are parallel to each other.

Patent Document 1 discloses an invention relating to a mounting structure of an electric power steering device to a vehicle body. In the electric power steering device shown in Patent Document 1, the pinion shaft and the electric motor are supported on both sides along the axis of the gearbox, and the steering side mount portion and the electric motor provided in the vicinity of the portion supporting the pinion shaft. The gearbox is connected to the vehicle body at two places of the motor side mount portion provided near the portion that supports the motor. Further, in the mounting structure of Patent Document 1, the motor side mount portion is fixed to the vehicle body via a rubber bush, and the steering side mount portion is fixed to the vehicle body via a metal bush having a spring constant higher than that of the rubber bush. This makes it possible to reduce the vibration noise of the electric motor while maintaining the steering response.

Japanese Unexamined Patent Publication No. 2014-84079

However, according to the mounting structure of Patent Document 1, the displacement amount of the gearbox when the tire on the motor side mount portion side elastically fixed to the vehicle body is steered is the steering side fixed rigidly to the vehicle body. It will be larger than the displacement of the gearbox when the tire on the mount side is steered. For this reason, there is a difference in responsiveness between when the tire is steered to the left and when the tire is steered to the right, which may cause the driver to feel uncomfortable. Further, according to the mounting structure of Patent Document 1, since the load sharing ratio of the steering side mount portion is higher than that of the motor side mount portion, it is necessary to firmly design the metal bush mounting portion, and the cost and weight are correspondingly increased. May increase.

An object of the present invention is to provide a steering gearbox mounting structure and a mounting method thereof in which the difference in responsiveness at the time of turning left and right is small.

(1) The steering gearbox mounting structure according to the present invention is a vehicle body (for example, a front side frame 2L described later) of a gearbox (for example, a gearbox 52 described later) that accommodates a rack shaft displaced in the vehicle width direction by a steering force. , 2R and the front subframe 3), the gearbox is a first mounting portion (for example, a left mount portion 57L described later) provided at a position separated along the axial direction of the rack axis. And a second mounting portion (for example, the right mount portion 57R described later) and a third mounting portion (for example, the center described later) provided between the first mounting portion and the second mounting portion along the axial direction. The mount portion 57C) and the third mounting portion are fixed to the vehicle body via an elastic member (for example, a rubber member 592 of the mount bush 59 described later), and the first mounting portion is fixed to the vehicle body. The second mounting portion is more rigidly fixed to the vehicle body than the third mounting portion.

(2) In this case, it is preferable that the first mounting portion and the second mounting portion are fixed to the vehicle body without an elastic member.

(3) In this case, the pinion shaft (for example, the pinion shaft 51 described later) to which the steering force is input meshes with the rack shaft on one side along the vehicle front-rear direction, and the first mounting portion and the first mounting portion. The two mounting portions are provided on one side of the rack shaft along the vehicle front-rear direction, and the third mounting portion is provided on the other side of the rack shaft along the vehicle front-rear direction. Is preferable.

(4) In this case, the gearbox is attached to a subframe of the vehicle body (for example, a front subframe 3 described later), and the subframe is a first front / rear portion (for example, described later) extending along the vehicle front-rear direction. Left front and rear portion 31L) and second front and rear portion (for example, right front and rear portion 31R described later), and a connecting portion (for example, a connecting portion) extending along the vehicle width direction and connecting the first front and rear portion and the second front and rear portion. The first mounting portion is provided with a connecting portion 32) described later, and the first mounting portion is mounted on a first fixing portion (for example, the left seat surface 34L described later) provided in the first front and rear portions, and the second mounting portion is provided. Is attached to a second fixing portion (for example, the right seat surface 34R described later) provided in the second front and rear portions, and the third mounting portion is a third fixing portion (for example, for example) provided in the connecting portion. It is preferable to attach it to the central seat surface 34C) described later.

(5) In this case, the gearbox is attached to a subframe of the vehicle body (for example, a front subframe 3 described later), and the subframe is a first fixing portion (for example, to which the first mounting portion is attached). The left seat surface 34L described later), the second fixing portion to which the second mounting portion is attached (for example, the right seat surface 34R described later), and the third fixing portion (for example, described later) to which the third mounting portion is attached. The central seat surface 34C), the main fixing portion attached to the main frame of the vehicle body (for example, the left bulging portion 35L and the right bulging portion 35R described later), and the first fixed portion in a state of being attached to the first fixing portion. It is preferable to provide a stiffener (for example, a left stiffener 33L and a right stiffener 33R described later) for connecting the second mounting portion and the main fixing portion in a state of being mounted on the first mounting portion or the second fixing portion. ..

(6) The steering gearbox mounting method according to the present invention is the mounting method for mounting the gearbox according to any one of (1) to (4) to the vehicle body, and is the first mounting portion and the second mounting portion. Is fixed to the vehicle body, and then the third mounting portion is fixed to the vehicle body.

(1) In the present invention, the first mounting portion and the second mounting portion provided at positions separated along the axial direction of the rack shaft are fixed to the vehicle body more rigidly than the third mounting portion, thereby left and right. The difference in the amount of displacement of the gearbox with respect to the vehicle body at the time of steering can be reduced, and the difference in responsiveness at the time of turning left and right can also be reduced. Further, in the present invention, by fixing the gearbox to the vehicle body at the three parts of the first mounting part, the second mounting part, and the third mounting part, the axis line passing through the first mounting part and the second mounting part is centered. It is possible to suppress the rotation of the gearbox with respect to the vehicle body. In the present invention, since the third mounting portion is provided between the first mounting portion and the second mounting portion along the axial direction, the left and right sides resulting from elastically fixing the third mounting portion. It is possible to reduce the influence on the difference in responsiveness at the time of steering.

By the way, the mounting portion of the gearbox may be slightly lifted from the seating surface of the vehicle body due to variations in the manufacturing of the gearbox or the vehicle body. In this case, if the mounting part of the gearbox is to be fixed to the seating surface of the vehicle body with bolts, for example, it is necessary to increase the axial force of the bolt so that there is no gap between the mounting part and the seating surface, and then tighten the bolt diameter. It may be necessary to increase the size of the seat or increase the strength of the seat surface. On the other hand, in the present invention, the first mounting portion and the second mounting portion are provided on the vehicle body by providing the first mounting portion and the second mounting portion rigidly fixed to the vehicle body at positions separated from each other along the axial direction. It is possible to secure a large amount of elastic deformation on the vehicle body side when fixing. Therefore, when the first mounting portion and the second mounting portion are fixed to the vehicle body with, for example, bolts, the vehicle body side can be elastically deformed in order to eliminate the floating caused by the variation during manufacturing. The first mounting portion and the second mounting portion can be fixed to the vehicle body without increasing the axial force. Since the distance between the third mounting portion and the first mounting portion and the distance between the third mounting portion and the second mounting portion are shorter than the distance between the first mounting portion and the second mounting portion. The amount of elastic deformation on the vehicle body side when the third mounting portion is fixed to the vehicle body is smaller than the amount of elastic deformation on the vehicle body side when the first mounting portion and the second mounting portion are fixed to the vehicle body. On the other hand, in the present invention, by fixing the third mounting portion to the vehicle body via the elastic member, it is possible to eliminate the floating caused by the variation during manufacturing without increasing the axial force of the bolt.

(2) In the present invention, by fixing the first mounting portion and the second mounting portion to the vehicle body without using an elastic member, the first mounting portion and the second mounting portion are fixed more rigidly than the third mounting portion. However, the cost of the elastic member can be reduced.

(3) In the present invention, the displacement of the pinion shaft can be suppressed by providing the first mounting portion and the second mounting portion fixed to the rigid on the pinion shaft side along the vehicle front-rear direction with respect to the rack shaft. Therefore, the responsiveness of the tire to the steering force can be further enhanced, and the tire reaction force and the like can be easily transmitted to the steering wheel. Further, in the present invention, by providing the third mounting portion on the side opposite to the first mounting portion and the second mounting portion across the rack shaft, the axis and the third mounting portion passing through the first mounting portion and the second mounting portion are provided. Since a long distance along the vehicle front-rear direction can be secured, the rotation of the gearbox around this axis with respect to the vehicle body can be suppressed more effectively.

(4) In the present invention, the first mounting portion and the second mounting portion are rigidly fixed to the first front and rear portions and the second front and rear portions, which are easy to support the load along the vehicle front-rear direction among the subframes. By providing the portion and the second fixing portion, the support rigidity of the gearbox by the subframe can be increased. Further, in the present invention, a third mounting portion, which is not required to have support rigidity as compared with the first mounting portion and the second mounting portion, is provided in the connecting portion connecting the first front and rear portions and the second front and rear portions. By fixing to the fixed portion, the degree of freedom in arranging the gearbox can be increased.

(5) In the present invention, the vehicle body is divided into a subframe to which the gearbox is attached and a main frame to which the subframe is attached. Further, in the present invention, the first mounting portion in the state of being mounted on the first fixing portion or the second mounting portion in the state of being mounted on the second fixing portion and the main fixing portion mounted on the main frame are connected by a stiffener. do. As a result, the support rigidity of the gearbox by the vehicle body can be further increased, so that the responsiveness at the time of turning left and right can be further enhanced.

(6) As described above, the mounting portion of the gearbox may slightly float from the seating surface of the vehicle body due to variations in the manufacturing of the gearbox or the vehicle body. For this reason, if the gearbox is to be fixed to the vehicle body with, for example, bolts at the three mounting portions, the gap between the mounting portion to be fixed at the end (third) and the seat surface becomes large, and the axial force of the bolts is increased. Need to increase. On the other hand, in the present invention, the first mounting portion and the second mounting portion are fixed to the vehicle body, and then the third mounting portion is fixed to the vehicle body. As described above, the first mounting portion and the second mounting portion are provided at positions separated from each other along the axial direction. Therefore, by fixing the first mounting portion and the second mounting portion to the vehicle body before fixing the third mounting portion to the vehicle body, the vehicle body side when fixing the first mounting portion and the second mounting portion to the vehicle body. Since a large amount of elastic deformation can be secured, the first mounting portion and the second mounting portion can be fixed to the vehicle body without increasing the axial force of the bolt. Further, by fixing the third mounting portion at the end, the gap between the third mounting portion and the seating surface of the vehicle body tends to increase, but in the present invention, the third mounting portion is elastic with respect to the vehicle body. By fixing to, the third mounting portion can be fixed to the vehicle body without increasing the axial force of the bolt.

It is a figure which looked at the inside of the engine room of the front part of the vehicle to which the steering gear box mounting structure and the mounting method which concerns on one Embodiment of this invention are applied, from the front side in the traveling direction. It is a top view of the front subframe. It is a front view of the front subframe. It is a rear view of the front subframe. FIG. 3B is a cross-sectional view taken along the line IV-IV in FIG. 3B. FIG. 3B is a cross-sectional view taken along the line VV in FIG. 3B.

Hereinafter, the steering gearbox mounting structure and the steering gearbox mounting method according to the embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a view of the inside of the engine room 1 at the front of the vehicle V to which the steering gearbox mounting structure and the steering gearbox mounting method according to the present embodiment are applied, as viewed from the front side in the front-rear direction of the vehicle. In the following, a vehicle V in which a driver-operable steering handle is provided on the right side in the vehicle width direction, a so-called right-hand drive vehicle V, will be described, but the present invention is not limited to this. The present invention can also be applied to vehicles with left-hand drive. Further, in FIG. 1, the configuration of the stiffeners 33L and 33R, which will be described later, is not shown.

The engine room 1 of the vehicle V includes a left front side frame 2L and a right front side frame 2R that form a part of the vehicle body, and a front subframe that forms a part of the vehicle body and is attached to these front side frames 2L and 2R. 3 and a steering device 5 attached to the front subframe 3 are provided.

The front side frames 2L and 2R are columnar and extend along the front-rear direction of the vehicle. The front side frames 2L and 2R are separated from each other along the vehicle width direction and are provided substantially in parallel. The left front side frame 2L is provided on the left side in the vehicle width direction, and the right front side frame 2R is provided on the right side in the vehicle width direction. The front subframe 3 is provided so as to bridge between the front side frames 2L and 2R. Further, the steering device 5 is supported by the front subframe 3 between the front side frames 2L and 2R.

The steering device 5 converts the rotational movement of the steering handle (not shown) by the driver in the driver's seat provided on the right side in the vehicle width direction into a movement along the vehicle width direction of the rack axis (not shown). By doing so, the left and right front wheels are steered in the direction of travel.

The steering device 5 includes a pinion shaft 51 extending in the vertical direction, a rack shaft extending along the vehicle width direction (not shown), a gearbox 52 accommodating the tip of the pinion shaft 51, and both ends of the rack shaft. A rod-shaped left tie rod 53L and a right tie rod 53R connected via a joint (not shown), and a left boot 54L and a right boot 54R covering the joints provided at both ends of the rack shaft. The left and right front wheels are connected to the tie rods 53L and 53R, respectively.

The gearbox 52 includes a cylindrical gearbox body 55 extending along the vehicle width direction, a left bracket 56L provided at the left end portion 55L on the left side of the gearbox body 55 in the vehicle width direction, and a gearbox body 55. The right bracket 56R provided at the right end 55R on the right side in the vehicle width direction, the central bracket 56C provided between both ends 55L and 55R of the gearbox main body 55 along the vehicle width direction, and the gearbox main body. Of 55, a pinion shaft support portion 58 provided between the right bracket 56R and the center bracket 56C along the vehicle width direction is provided. The gearbox body 55, the left bracket 56L, the right bracket 56R, the center bracket 56C, and the pinion shaft support portion 58 are made of, for example, aluminum.

The gearbox main body 55 supports a rack shaft (not shown) inside the gearbox body 55 in a freely displaceable manner along the vehicle width direction. The pinion shaft support portion 58 is provided on the front side of the gearbox main body 55 in the front-rear direction of the vehicle with respect to the rack shaft. The pinion shaft support portion 58 rotatably supports the tip portion of the pinion shaft 51 extending in the vertical direction inside the pinion shaft support portion 58. The tip of the pinion shaft 51 meshes with the rack shaft inside the pinion shaft support portion 58 and the gearbox main body 55. More specifically, the tip end portion of the pinion shaft 51 meshes with the rack shaft on the front side along the vehicle front-rear direction. Therefore, when a steering force is input to the pinion shaft 51 by the driver's operation of the steering handle, the pinion shaft 51 rotates and the rack shaft is displaced to the left or right along the vehicle width direction. The left and right front wheels are steered by this.

As described above, in the present embodiment, the case where the tip end portion of the pinion shaft 51 is meshed with the rack shaft on the front side along the vehicle front-rear direction will be described, but the present invention is not limited to this. The tip of the pinion shaft may be meshed with respect to the rack shaft on the rear side along the vehicle front-rear direction.

The left bracket 56L has an arm shape extending forward from the left end portion 55L of the gearbox main body 55 along the vehicle front-rear direction. In other words, the left bracket 56L extends toward the pinion shaft 51 along the vehicle front-rear direction with respect to the rack shaft. A left mount portion 57L as a cylindrical first mounting portion is provided at the tip portion of the left bracket 56L.

The right bracket 56R has an arm shape extending forward from the right end portion 55R of the gearbox main body 55 along the vehicle front-rear direction. In other words, the right bracket 56R extends toward the pinion shaft 51 along the vehicle front-rear direction with respect to the rack shaft. A right mount portion 57R as a cylindrical second mounting portion is provided at the tip end portion of the right bracket 56R.

The central bracket 56C has an arm shape extending rearward from the gearbox main body 55 along the vehicle front-rear direction. In other words, the central bracket 56C extends to the side opposite to the pinion shaft 51 along the vehicle front-rear direction with respect to the rack shaft. At the tip of the central bracket 56C, a central mount portion 57C as a cylindrical third mounting portion is provided.

The gearbox body 55 is fixed to the front subframe 3 by fastening means (not shown) at the three portions of the left mount portion 57L, the right mount portion 57R, and the center mount portion 57C. In the present embodiment, a case where a bolt is used as the fastening means will be described, but the present invention is not limited to this.

As shown in FIG. 1, the left mount portion 57L and the right mount portion 57R are provided at positions separated from each other along the axial direction of the rack axis, that is, the vehicle width direction. The central mount portion 57C is provided between the left mount portion 57L and the right mount portion 57R along the vehicle width direction. Further, the left mount portion 57L and the right mount portion 57R are provided on the front side (that is, the pinion shaft 51 side) along the vehicle front-rear direction with respect to the rack axis in a plan view, and the central mount portion 57C is a rack axis in a plan view. On the other hand, it is provided on the rear side (that is, on the side opposite to the pinion shaft 51) along the vehicle front-rear direction.

FIG. 2 is a plan view of the front subframe 3. FIG. 3A is a front view of the front subframe 3 as viewed from the front side in the front-rear direction of the vehicle, and FIG. 3B is a rear view of the front subframe 3 as viewed from the rear side in the front-rear direction of the vehicle. Regarding the configuration of the steering device in FIG. 2, only the left mount portion 57L, the right mount portion 57R, and the center mount portion 57C are shown for easy understanding. Further, in FIGS. 2, 3A and 3B, the axis O of the rack shaft supported by the gearbox main body fixed to the front subframe 3 is shown by a broken line.

The front subframe 3 is formed by joining an upper panel 3a constituting the upper part and a lower panel 3b constituting the lower part. Therefore, the inside of the front subframe 3 is hollow. The front subframe 3 has a left front / rear portion 31L extending along the vehicle front-rear direction on the left side in the vehicle width direction, a right front / rear portion 31R extending along the vehicle front-rear direction on the right side in the vehicle width direction, and both extending along the vehicle width direction. It includes a connecting portion 32 for connecting the front and rear portions 31L and 31R, a left stiffener 33L provided on the left front and rear portion 31L, and a right stiffener 33R provided on the right front and rear portion 31R.

A central seat surface 34C as a third fixing portion to which the central mount portion 57C of the gearbox main body is attached is formed at substantially the center of the upper surface of the connecting portion 32 in the vehicle width direction. As shown in FIG. 2, the central seat surface 34C is provided on the rear side of the upper surface of the connecting portion 32 in the front-rear direction of the vehicle with respect to the axis O of the rack axis in a plan view.

The left front-rear portion 31L extends along the vehicle front-rear direction on the vertically lower side of the left front side frame 2L extending along the vehicle front-rear direction on the left side in the vehicle width direction.

On the front side of the upper surface of the left front and rear portion 31L in the front and rear direction of the vehicle from the axis O of the rack axis, the left seat surface 34L as the first fixing portion to which the left mount portion 57L of the gearbox body is attached and the left front side frame. A left bulging portion 35L as a main mounting portion to be attached to the 2L is formed. The left seat surface 34L is provided on the upper surface of the left front and rear portion 31L on the side opposite to the central seat surface 34C with the axis O of the rack axis interposed therebetween. The left bulging portion 35L is provided outside the vehicle width direction and slightly forward side along the vehicle front-rear direction with respect to the left seat surface 34L in a plan view.

As shown in FIGS. 3A and 3B, the left bulging portion 35L bulges upward in the vertical direction, and at the tip thereof, the first left main seat surface 36L attached to the left front side frame 2L. And the left vice seat surface 37L to which the end portion of the left stiffener 33L is attached are formed. The left vice seat surface 37L is provided slightly inside the first left main seat surface 36L in the vehicle width direction, that is, slightly on the left seat surface 34L side along the vehicle width direction. As shown in FIG. 3, the first left main seat surface 36L and the left vice seat surface 37L provided at the tip of the left bulging portion 35L have the left seat surface 34L, the central seat surface 34C, and the axis O of the rack shaft. It is on the upper side in the vertical direction.

Further, a second left main seat surface 38L to be attached to the left front side frame 2L is formed on the rear side in the vehicle front-rear direction of the upper surface of the left front-rear portion 31L with respect to the axis O of the rack axis. As shown in FIG. 3, the second left main seat surface 38L is vertically lower than the first left main seat surface 36L and the axis O of the rack axis. The left front and rear portions 31L are attached to the left front side frame 2L on the first left main seat surface 36L and the second left main seat surface 38L on both sides in the vehicle front-rear direction with the axis O of the rack axis interposed therebetween.

The right front-rear portion 31R extends along the vehicle front-rear direction on the vertically lower side of the right front side frame 2R extending along the vehicle front-rear direction on the right side in the vehicle width direction.

On the front side of the upper surface of the right front and rear portion 31R in the front and rear direction of the vehicle from the axis O of the rack axis, the right seat surface 34R as a second fixing portion to which the right mount portion 57R of the gearbox body is attached and the right front side frame. A right bulging portion 35R attached to the 2R is formed. The right seat surface 34R is provided on the upper surface of the right front and rear portion 31R on the opposite side of the central seat surface 34C with the axis O of the rack axis interposed therebetween. On the other hand, it is provided on the outside in the vehicle width direction and slightly on the front side along the vehicle front-rear direction.

As shown in FIGS. 3A and 3B, the right bulging portion 35R bulges upward in the vertical direction, and at the tip thereof, the first right main seat surface 36R attached to the right front side frame 2R. And the right vice seat surface 37R to which the end of the right stiffener 33R is attached. The right vice seat surface 37R is provided slightly inside the first right main seat surface 36R in the vehicle width direction, that is, slightly on the right seat surface 34R side along the vehicle width direction. As shown in FIG. 3, the height of the first right main seat surface 36R and the right vice seat surface 37R provided at the tip portion of the right bulging portion 35R along the vertical direction is the tip portion of the left bulging portion 35L. It is substantially equal to the first left main seat surface 36L and the left vice seat surface 37L provided in. That is, the first right main seat surface 36R and the right vice seat surface 37R provided at the tip of the right bulging portion 35R are vertically above the right seat surface 34R, the central seat surface 34C, and the axis O of the rack axis. On the side.

Further, a second right main seat surface 38R to be attached to the right front side frame 2R is formed on the rear side in the vehicle front-rear direction of the upper surface of the right front-rear portion 31R with respect to the axis O of the rack axis. As shown in FIG. 3, the second right main seat surface 38R is vertically lower than the first right main seat surface 36R and the axis O of the rack axis. The right front and rear portions 31R are attached to the right front side frame 2R on the first right main seat surface 36R and the second right main seat surface 38R on both sides in the vehicle front-rear direction with the axis O of the rack axis interposed therebetween.

The left stiffener 33L extends along the vehicle width direction and connects the left mount portion 57L and the tip portion of the left bulging portion 35L in a state of being attached to the left seat surface 34L. More specifically, the left stiffener 33L is fixed to the left vice seat surface 37L of the left bulging portion 35L by a bolt (not shown) at the outer end portion 331L in the vehicle width direction, and is not shown at the inner end portion 332L in the vehicle width direction. It is fixed to the left mount portion 57L in a state of being attached to the left seat surface 34L by a bolt. As shown in FIG. 3A, the left vice seat surface 37L is higher in the vertical direction than the left mount portion 57L in the state of being attached to the left seat surface 34L. Therefore, the left stiffener 33L inclines downward in the vertical direction from the outer end portion 331L in the vehicle width direction toward the inner end portion 332L in the vehicle width direction.

The right stiffener 33R extends along the vehicle width direction and connects the right mount portion 57R and the tip portion of the right bulging portion 35R in a state of being attached to the right seat surface 34R. More specifically, the right stiffener 33R is fixed to the right vice seat surface 37R of the right bulging portion 35R by a bolt (not shown) at the outer end portion 331R in the vehicle width direction, and is not shown at the inner end portion 332R in the vehicle width direction. It is fixed to the right mount portion 57R in a state of being attached to the right seat surface 34R by a bolt. As shown in FIG. 3A, the right vice seat surface 37R is higher in the vertical direction than the right mount portion 57R in the state of being attached to the right seat surface 34R. Therefore, the right stiffener 33R inclines downward in the vertical direction from the outer end 331R in the vehicle width direction toward the inner end 332R in the vehicle width direction.

FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3B, and is a diagram for explaining a fastening structure of the central mount portion 57C to the connecting portion 32. As shown in FIG. 4, the central mount portion 57C has a cylindrical shape in which a through hole 571C extending in the vertical direction is formed in the center thereof. A cylindrical mount bush 59 is press-fitted into the through hole 571C of the central mount portion 57C.

The mount bush 59 includes a cylindrical iron collar 591 extending along the vertical direction and a rubber member 592 as a cylindrical elastic member provided on the outer peripheral surface of the iron collar 591. The rubber member 592 is joined to the outer peripheral surface of the iron collar 591. More specifically, as the mount bush 59, one manufactured by casting an iron collar 591 into a rubber member 592 is used. Flange portions 592a and 592b are provided at both ends of the rubber member 592, respectively. Therefore, a C-shaped mating portion 592c is formed on the outer peripheral portion of the rubber member 592 in a cross-sectional view. The mount bush 59 is press-fitted into the through hole 571C by aligning the mating portion 592c of the rubber member 592 with the inner peripheral portion of the through hole 571C of the central mount portion 57C.

The central mount portion 57C inserts a bolt 60 into a through hole 593 formed in the center of the mount bush 59, and further tightens the bolt 60 to a nut 61 provided on the back surface of the central seat surface 34C in the upper panel 3a. Thereby, it is attached to the central seat surface 34C. That is, the central mount portion 57C is elastically fixed to the central seat surface 34C via the rubber member 592 of the mount bush 59.

The lengths of the iron collar 591 and the rubber member 592 along the axis of the bolt 60 are substantially the same. Further, the length of the iron collar 591 and the rubber member 592 along the axis of the bolt 60 is slightly longer than the length of the central mount portion 57C along the axis of the bolt 60. Therefore, when the bolt 60 is tightened to the nut 61, the iron collar 591 of the mount bush 59 is in close contact with the central bearing surface 34C and the bolt 60 at both end surfaces thereof, and is held between the central bearing surface 34C and the bolt 60. .. Further, when the bolt 60 is tightened to the nut 61, the central mount portion 57C does not come into direct contact with the bolt 60, the central bearing surface 34C, and the iron collar 591, but the bolt 60 is passed through the rubber member 592 of the mount bush 59. , Central bearing surface 34C, and iron collar 591. Therefore, the vibration transmitted to the central mount portion 57C and the displacement of the central mount portion 57C with respect to the bolt 60, the central seat surface 34C, and the iron collar 591 are absorbed by the rubber member 592.

FIG. 5 is a cross-sectional view taken along the line VV in FIG. 3B, and is a diagram for explaining a fastening structure of the left mount portion 57L to the left front and rear portions 31L. Since the fastening structure of the right mount portion 57R to the right front and rear portion 31R is almost the same as the fastening structure of the left mount portion 57L to the left front and rear portion 31L, illustration and detailed description thereof will be omitted.

As shown in FIG. 5, the left mount portion 57L has a cylindrical shape in which a through hole 571L extending in the vertical direction is formed in the center thereof. The lower surface 572L of the left mount portion 57L is in contact with the left seat surface 34L, and the upper surface 573L of the left mount portion 57L is in contact with the end portion 332L of the left stiffener 33L. The left mount portion 57L and the end portion 332L of the left stiffener 33L are provided with a bolt 62 inserted into the through hole 571 from the left stiffener 33L side, and the bolt 62 is further provided on the back surface of the left seat surface 34L of the upper panel 3a. It is attached to the left seat surface 34L by tightening it to the nut 63. That is, unlike the central mount portion 57C, the left mount portion 57L and the end portion 332L of the left stiffener 33L are fixed to the left seat surface 34L without an elastic member. Therefore, the left mount portion 57L and the end portion 332L of the left stiffener 33L are more rigidly fixed to the left seat surface 34L than the central mount portion 57C. The right mount portion 57R and the end portion 332R of the right stiffener 33R are also similarly fixed to the right seat surface 34R more rigidly than the central mount portion 57C without using an elastic member.

As described above, the gearbox 52 of the steering device 5 has the left seat surface 34L and the right seat surface 34R of the front subframe 3 in the three portions of the left mount portion 57L, the right mount portion 57R, and the center mount portion 57C, respectively. And fixed to the central seat surface 34C.

Next, the order in which the gearbox 52 of the steering device 5 is attached to the front subframe 3 will be described. In the gearbox 52, first, the left mount portion 57L and the right mount portion 57R, and the left stiffener 33L and the right stiffener 33R are rigidly fixed to the left seat surface 34L and the right seat surface 34R as described above, and then the central mount portion 57C. Is attached to the front subframe 3 by fixing to the central seat surface 34C via a mount bush 59 provided with a rubber member 592 as described above.

Regarding the order of fixing the left mount portion 57L and the right mount portion 57R, in the case of a vehicle with a right-hand drive as in the present embodiment, the right mount portion 57R closer to the pinion shaft support portion 58 is placed first on the right seat surface 34R. After fixing to, it is preferable to fix the left mount portion 57L to the left seat surface 34L, but the present invention is not limited to this. The left mount portion 57L and the right mount portion 57R may be fixed to the left seat surface 34L and the right seat surface 34R at the same time, or the left mount portion 57L may be fixed to the left seat surface 34L first, and then the right mount portion 57R may be fixed. It may be fixed to the right seat surface 34R. Further, in the case of a left-hand drive vehicle, it is preferable to first fix the left mount portion closer to the pinion shaft support portion to the left seat surface and then fix the right mount portion to the right seat surface.

According to the steering gearbox mounting structure and mounting method according to the present embodiment, the following effects are obtained.
(1) In the present embodiment, the left mount portion 57L and the right mount portion 57R provided at positions separated along the axial direction of the rack axis are fixed to the front subframe 3 more rigidly than the center mount portion 57C. As a result, the difference in the amount of displacement of the gearbox 52 with respect to the vehicle body during left and right steering can be reduced, and the difference in responsiveness during left and right steering can also be reduced. Further, in the present embodiment, the left mount portion 57L and the right mount portion 57R are formed by fixing the gearbox 52 to the front subframe 3 at the three portions of the left mount portion 57L, the right mount portion 57R, and the center mount portion 57C. It is possible to suppress the rotation of the gearbox 52 with respect to the vehicle body around the passing axis. In the present embodiment, the central mount portion 57C is provided between the left mount portion 57L and the right mount portion 57R along the axial direction, which is caused by elastically fixing the central mount portion 57C. It is possible to reduce the influence on the difference in responsiveness when turning left and right.

On the other hand, in the present embodiment, the left mount portion 57L and the right mount portion 57R, which are rigidly fixed to the front subframe 3, are provided at positions separated from each other along the axial direction, whereby the left mount portion 57L and the right mount portion are provided. When fixing the 57R to the front subframe 3, a large amount of elastic deformation on the front subframe 3 side can be secured. Therefore, when the left mount portion 57L and the right mount portion 57R are fixed to the front subframe 3 with bolts, the front subframe 3 side may be elastically deformed in order to eliminate the floating caused by the variation during manufacturing. Therefore, the left mount portion 57L and the right mount portion 57R can be fixed to the front subframe 3 without increasing the axial force of the bolt. Since the distance between the center mount portion 57C and the left mount portion 57L and the distance between the center mount portion 57C and the right mount portion 57R are shorter than the distance between the left mount portion 57L and the right mount portion 57R. The amount of elastic deformation on the front subframe 3 side when the central mount portion 57C is fixed to the front subframe 3 is the front subframe 3 when the left mount portion 57L and the right mount portion 57R are fixed to the front subframe 3. Less than the amount of elastic deformation on the side. On the other hand, in the present embodiment, by fixing the central mount portion 57C to the front subframe 3 via the mount bush 59 provided with the rubber member 592, the floating due to the variation in manufacturing without increasing the axial force of the bolt. Can be resolved.

(2) In the present embodiment, the left mount portion 57L and the right mount portion 57R are fixed to the front subframe 3 without an elastic member, so that the left mount portion 57L and the right mount portion 57R are fixed from the central mount portion 57C. It is possible to reduce the cost of the elastic member while fixing it to the rigid.

(3) In the present embodiment, the displacement of the pinion shaft 51 can be suppressed by providing the left mount portion 57L and the right mount portion 57R fixed to the rigid on the pinion shaft 51 side along the vehicle front-rear direction with respect to the rack shaft. .. Therefore, the responsiveness of the tire to the steering force can be further enhanced, and the tire reaction force and the like can be easily transmitted to the steering wheel. Further, in the present embodiment, by providing the central mount portion 57C on the side opposite to the left mount portion 57L and the right mount portion 57R across the rack shaft, the axis and the center mount portion passing through the left mount portion 57L and the right mount portion 57R are provided. Since a long distance from the 57C along the vehicle front-rear direction can be secured, the rotation of the gearbox 52 about the axis with respect to the front subframe 3 can be more effectively suppressed.

(4) In the present embodiment, the left mount portion 57L and the right mount portion 57R are rigidly fixed to the left front / rear portion 31L and the right front / rear portion 31R that easily support the load along the vehicle front / rear direction among the front subframe 3. By providing the left seat surface 34L and the right seat surface 34R, the support rigidity of the gearbox 52 by the front subframe 3 can be increased. Further, in the present embodiment, the central mount portion 57C, which does not require support rigidity as compared with the left mount portion 57L and the right mount portion 57R, is provided in the connecting portion 32 connecting the left front and rear portions 31L and the right front and rear portions 31R. By fixing to the central seat surface 34C, the degree of freedom in arranging the gearbox 52 can be increased.

(5) In the present embodiment, the vehicle body is divided into a front subframe 3 to which the gearbox 52 is attached and front side frames 2L and 2R to which the front subframe 3 is attached. Further, in the present embodiment, the left mount portion 57L attached to the left seat surface 34L and the left bulging portion 35L attached to the left front side frame 2L are connected by the left stiffener 33L and attached to the right seat surface 34R. The right mount portion 57R and the right bulging portion 35R attached to the right front side frame 2R in the raised state are connected by the right stiffener 33R. As a result, the support rigidity of the gearbox 52 by the frames 2L, 2R, and 3 can be further increased, so that the responsiveness at the time of turning left and right can be further enhanced.

(6) In the present embodiment, the left mount portion 57L and the right mount portion 57R are fixed to the front subframe 3, and then the center mount portion 57C is fixed to the front subframe 3. As described above, the left mount portion 57L and the right mount portion 57R are provided at positions separated from each other in the axial direction. Therefore, by fixing the left mount portion 57L and the right mount portion 57R to the front subframe 3 before fixing the center mount portion 57C to the front subframe 3, the left mount portion 57L and the right mount portion 57R are fixed to the front subframe. Since a large amount of elastic deformation on the front subframe 3 side can be secured when fixing to 3, the left mount portion 57L and the right mount portion 57R can be fixed to the front subframe 3 without increasing the axial force of the bolt. Further, by fixing the central mount portion 57C at the end, the gap between the central mount portion 57C and the central seat surface 34C of the front subframe 3 tends to increase, but in the present embodiment, the central mount portion 57C Is elastically fixed to the front subframe 3, so that the central mount portion 57C can be fixed to the front subframe 3 without increasing the axial force of the bolt.

Although one embodiment of the present invention has been described above, the present invention is not limited to this. Within the scope of the present invention, the detailed configuration may be changed as appropriate.

V ... Vehicle 1 ... Engine room 2L ... Left front side frame (body, main frame)
2R ... Right front side frame (body, main frame)
3 ... Front subframe (body, subframe)
31L ... Left front and rear part (first front and rear part)
31R ... Right front and rear part (second front and rear part)
32 ... Connecting part 33L ... Left Stiffna (Stiffna)
33R ... Right Stifna (Stifna)
34L ... Left seat surface (first fixed part)
34R ... Right seat surface (second fixed part)
34C ... Central seat surface (third fixed part)
35L ... Left bulge (main mounting part)
35R ... Right bulging part (main mounting part)
5 ... Steering device 51 ... Pinion shaft 52 ... Gearbox 55 ... Gearbox body 56L ... Left bracket 56R ... Right bracket 56C ... Center bracket 57L ... Left mount part (first mounting part)
57R ... Right mount part (second mounting part)
57C ... Central mount part (third mounting part)
58 ... Pinion shaft support 59 ... Mount bush 591 ... Iron collar 592 ... Rubber member (elastic member)

Claims (6)

It is a steering gearbox mounting structure for the vehicle body of the gearbox that accommodates the rack axle that is displaced in the vehicle width direction due to steering force.
The gearbox includes a first mounting portion and a second mounting portion provided at positions separated from each other along the axial direction of the rack shaft, and the first mounting portion and the second mounting portion along the axial direction. It is fixed to the vehicle body at the third mounting portion provided between them.
The third mounting portion is fixed to the vehicle body via an elastic member, and is fixed to the vehicle body via an elastic member.
The steering gearbox mounting structure is characterized in that the first mounting portion and the second mounting portion are more rigidly fixed to the vehicle body than the third mounting portion. The steering gearbox mounting structure according to claim 1, wherein the first mounting portion and the second mounting portion are fixed to the vehicle body without an elastic member. The pinion shaft to which the steering force is input meshes with the rack shaft on one side along the vehicle front-rear direction.
The first mounting portion and the second mounting portion are provided on one side of the rack axis along the vehicle front-rear direction.
The steering gearbox mounting structure according to claim 1, wherein the third mounting portion is provided on the other side of the rack shaft along the vehicle front-rear direction. The gearbox is attached to the subframe of the vehicle body, and the gearbox is attached to the subframe of the vehicle body.
The subframe includes a first front-rear portion and a second front-rear portion extending along the vehicle front-rear direction, and a connecting portion extending along the vehicle width direction and connecting the first front-rear portion and the second front-rear portion. Prepare,
The first mounting portion is mounted on a first fixing portion provided on the first front and rear portions.
The second mounting portion is mounted on a second fixing portion provided on the second front and rear portions.
The steering gearbox mounting structure according to claim 1, wherein the third mounting portion is mounted on a third fixing portion provided in the connecting portion. The gearbox is attached to the subframe of the vehicle body, and the gearbox is attached to the subframe of the vehicle body.
The subframe is
The first fixing part to which the first mounting part is attached and
The second fixing part to which the second mounting part is attached and
The third fixing part to which the third mounting part is attached and
The main fixing part attached to the main frame of the car body and
It is characterized by including a stiffener for connecting the first mounting portion in a state of being attached to the first fixing portion or the second mounting portion and the main fixing portion in a state of being attached to the second fixing portion. The steering gearbox mounting structure according to claim 1. A steering gearbox mounting method for mounting the gearbox according to any one of claims 1 to 5 to a vehicle body.
A steering gearbox mounting method comprising fixing the first mounting portion and the second mounting portion to the vehicle body and then fixing the third mounting portion to the vehicle body.

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